Driving method and system for adjustable light source LED

Abstract

The invention relates to a driving method and system for an adjustable light source LED, and the method comprises the steps: collecting the input voltage and target brightness of a light source in real time, and calculating an initial current set value of the light source; dynamically switching a constant-current dimming strategy and a linear dimming strategy according to the dimming threshold frequency of the light source; feeding back the real-time temperature of the light source through a temperature sensor, and performing temperature compensation on the driving current of the light source to obtain compensation current; determining the driving voltage of the light source by combining the light source forward voltage and the compensation current; and the duty ratio is adjusted in real time based on PID closed-loop control to obtain a real-time duty ratio, and the light source matching target brightness is adjusted based on the real-time duty ratio and the driving voltage. According to the invention, the accuracy and reliability of LED light source adjustment can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of light regulation, and particularly to a driving method, system, electronic device and non-transitory computer-readable storage medium for an adjustable light source LED. Background Art

[0002] Currently, the driving method of automotive LED headlights mainly adopts a constant current driving scheme, that is, a constant current source provides a stable current for the LED to ensure the brightness consistency and service life of the headlights. This method can effectively prevent light decay caused by current fluctuations and improve the reliability of the LED.

[0003] However, during low-brightness dimming, PWM modulation may introduce visible flicker, affecting the visual comfort of the driver. Secondly, the design of the constant current source needs to precisely match the current characteristics of the LED, otherwise it may lead to reduced energy efficiency or shortened LED life. Summary of the Invention

[0004] The present invention aims at the technical problems existing in the prior art, and provides a driving method, system, electronic device and non-transitory computer-readable storage medium for an adjustable light source LED that can improve the accuracy and reliability of LED light source regulation.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: The present invention provides a driving method for an adjustable light source LED, the method comprising: Real-time collecting the input voltage and target brightness of the light source, and calculating an initial current setting value of the light source; Dynamically switching a constant current dimming strategy and a linear dimming strategy according to the dimming threshold frequency of the light source; Feeding back the real-time temperature of the light source through a temperature sensor, and performing temperature compensation on the driving current of the light source to obtain a compensated current; Combining the forward voltage of the light source and the compensated current to determine the driving voltage of the light source; Based on PID closed-loop control, adjusting the duty cycle in real time to obtain a real-time duty cycle, and adjusting the light source to match the target brightness based on the real-time duty cycle and the driving voltage.

[0006] Optionally, the real-time collecting the input voltage and target brightness of the light source, and calculating an initial current setting value of the light source includes: Obtaining an initial current default value of the light source; Obtaining a brightness correction coefficient for matching the non-linear relationship between the target brightness and the current; Obtaining a sampling resistance value for real-time detecting the current of the light source; Process the default initial current value of the light source according to the input voltage of the light source, the target brightness, the sampling resistance value, and the brightness correction coefficient, and calculate the set value of the initial current of the light source.

[0007] Optionally, the set value of the initial current is expressed as: ; Wherein, is the set value of the initial current, is the target brightness, is the input voltage, is the sampling resistance value, is the default initial current value, is the brightness correction coefficient.

[0008] Optionally, the dynamic switching between the constant current dimming strategy and the linear dimming strategy according to the dimming threshold frequency of the light source includes: Obtain the feedback resistor for stabilizing the gain and response of the circuit Obtain the feedback capacitor for smoothing high-frequency noise and introducing phase compensation in the feedback loop; Determine the dimming threshold frequency according to the feedback resistor and the feedback capacitor; When the actual frequency of the light source is lower than the dimming threshold frequency, switch to the linear dimming strategy, and when the actual frequency of the light source is higher than or equal to the dimming threshold frequency, switch to the constant current dimming strategy.

[0009] Optionally, the dimming threshold frequency is expressed as: ; Wherein, is the dimming threshold frequency, is the feedback resistor, is the feedback capacitor.

[0010] Optionally, the method further includes determining the final drive current of the light source in the linear dimming strategy; the final drive current is determined through the following steps: Obtain the duty cycle representing the proportion of the time the light source is turned on per unit time; Obtain the time decay coefficient for describing the current decay characteristic of the light source over time; Obtain the current time during the dimming process; Determine the final drive current of the light source according to the duty cycle, the time decay coefficient, and the current time.

[0011] Optionally, the temperature compensation of the drive current of the light source by feeding back the real-time temperature of the light source through a temperature sensor to obtain a compensation current includes: Obtain the real-time temperature of the light source; Obtain the reference temperature of the light source under standard operating conditions; Obtain a temperature compensation coefficient for quantifying the influence degree of temperature change on the brightness of the light source; Determine the compensation current according to the final drive current, real-time temperature, reference temperature and temperature compensation coefficient of the light source.

[0012] Optionally, the determining the drive voltage of the light source by combining the forward voltage of the light source and the compensation current includes: Obtain the minimum forward voltage required to provide normal light emission of the light source; Obtain the circuit parasitic resistance of the light source; Obtain a dynamic current change gain for amplifying or suppressing the influence of current transients on the voltage; Determine the drive voltage of the light source according to the compensation current, the circuit parasitic resistance and the dynamic current change gain.

[0013] Optionally, the obtaining the real-time duty cycle by adjusting the duty cycle in real time based on PID closed-loop control includes: Obtain the brightness error of the difference between the target brightness and the actual brightness of the light source; Obtain the PID control parameters for calculating the real-time duty cycle; Determine the real-time duty cycle according to the duty cycle of the light source at the previous time point, the PID control parameters and the brightness error.

[0014] The present invention also provides a drive system for an adjustable light source LED, and the system includes: A current calculation module, configured to collect the input voltage and the target brightness of the light source in real time and calculate the initial current setting value of the light source; A strategy switching module, configured to dynamically switch between a constant current dimming strategy and a linear dimming strategy according to the dimming threshold frequency of the light source; A current compensation module, configured to feedback the real-time temperature of the light source through a temperature sensor and perform temperature compensation on the drive current of the light source to obtain a compensation current; A drive voltage module, configured to determine the drive voltage of the light source by combining the forward voltage of the light source and the compensation current; A light source adjustment module, configured to adjust the duty cycle in real time based on PID closed-loop control to obtain a real-time duty cycle, and adjust the light source to match the target brightness based on the real-time duty cycle and the drive voltage.

[0015] In addition, to achieve the above object, the present invention further provides an electronic device, including: a memory for storing a computer software program; a processor for reading and executing the computer software program, thereby implementing a driving method for an adjustable light source LED as described above.

[0016] In addition, to achieve the above object, the present invention further provides a non-transitory computer-readable storage medium, in which a computer software program is stored, and when the computer software program is executed by a processor, it implements a driving method for an adjustable light source LED as described above.

[0017] The beneficial effects of the present invention are as follows: (1) By introducing a hybrid dimming strategy, the present invention adopts constant current driving at high brightness to ensure brightness consistency, and automatically switches to the linear dimming mode at low brightness to avoid visible stroboscopic caused by PWM dimming. It greatly improves the visual comfort of the driver and reduces visual fatigue during long-term night driving.

[0018] (2) The present invention uses a temperature sensor to monitor the working temperature of the LED in real time and dynamically adjusts the driving current to prevent light decay and chip damage caused by overheating. Compared with the traditional constant current driving method, it can extend the service life of the LED by more than 20% and reduce the vehicle maintenance cost.

[0019] (3) Through the adaptive driving voltage adjustment mechanism, the present invention ensures that the LED works in the optimal voltage range and avoids energy loss caused by too high or too low voltage. Combined with the feedback closed-loop control, the overall energy efficiency is improved by about 15% - 25%, which is helpful for energy consumption-sensitive application scenarios such as new energy vehicles.

[0020] In summary, the present invention has significant advantages in eliminating low-brightness stroboscopic, extending the life of the LED, improving energy efficiency, and achieving high-precision brightness control. Through multi-dimensional closed-loop control and dynamic compensation technology, it not only solves the main pain points of the existing technology, but also realizes all-round optimization in the overall performance, and has broad market application prospects and strong technical barriers. Description of the Drawings

[0021] Figure 1 It is a flowchart of a driving method for an adjustable light source LED provided by the present invention; Figure 2 It is a schematic structural diagram of a driving system for an adjustable light source LED provided by the present invention; Figure 3 It is a schematic hardware structure diagram of a possible electronic device provided by the present invention; Figure 4 It is a schematic hardware structure diagram of a possible computer-readable storage medium provided by the present invention. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

[0023] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0024] In the description of the present invention, the term "for example" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "for example" in the present invention is not necessarily construed as being more preferred or more advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the present invention. In the following description, details are set forth for purposes of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be practiced without these specific details. In other instances, well-known structures and processes are not described in detail to avoid unnecessary details from obscuring the description of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

[0025] Please refer to Figure 1 , which provides a flowchart of a driving method for an adjustable light source LED of the present invention, including the following steps: Step 201, collect the input voltage and target brightness of the light source in real time, and calculate the initial current setting value of the light source.

[0026] In some embodiments, step 201 may include: Obtain the default initial current value of the light source; Obtain a brightness correction coefficient for matching the non-linear relationship between the target brightness and the current; Obtain a sampling resistance value for real-time detection of the current of the light source; Process the default initial current value of the light source according to the input voltage, target brightness of the light source, and the sampling resistance value and the brightness correction coefficient, and calculate the initial current setting value of the light source.

[0027] In some embodiments, the initial current setting value is expressed as: ; where is the initial current setting value, is the target brightness, is the input voltage, is the sampling resistance value, is the initial current default value, is the brightness correction coefficient.

[0028] In a specific implementation, is the corrected initial current setting value (unit: ampere), is the target brightness (unit: lumen or luminous intensity), is the input voltage (unit: volt), is the sampling resistance value (unit: ohm) for real-time detection of the LED current is the initial current default value (unit: ampere), which is the initial preset current when the system is powered on, is the brightness correction coefficient for matching the non-linear relationship between the target brightness and the current.

[0029] The core function of this formula is to dynamically adjust the initial drive current according to the input voltage and the target brightness to ensure stable LED brightness and avoid unnecessary energy loss.

[0030] The relationship between the brightness requirement and the current is usually not a simple linear relationship, so a correction coefficient is introduced for matching. For example, when the brightness requirement increases, the drive current needs to increase accordingly, but the current-brightness curve of the LED needs to be considered.

[0031] The actual value of the input voltage. If the voltage increases, in order to maintain stable brightness, the current should be appropriately reduced. The current detection voltage drop. The LED current is detected in real time through the sampling resistance, and the drive current is dynamically corrected to ensure that the actual output brightness is close to the target value.

[0032] If increases, the denominator becomes larger, resulting in decreasing. This can prevent overcurrent damage to the LED caused by voltage increase while keeping the brightness unchanged. If decreases, the denominator becomes smaller, increases to compensate for the brightness drop caused by insufficient input voltage. If a higher target brightness is required , the numerator increases, increases, providing a larger drive current to meet the brightness requirement.

[0033] In an actual circuit, the sensitivity of current detection can be balanced by adjusting the resistance value of , or can be dynamically adjusted to adapt to different LED models. The MCU can also be used to sample the voltage and current in real time, and the formula logic can be solidified into an embedded algorithm to adjust the LED driving strategy in real time.

[0034] For example, if = 12V, = 0.1Ω, = 1000lm, = 0.8, = 1A: ; In this way, the LED will start with a current close to 66mA and continuously adjust according to the real-time feedback.

[0035] In summary, the present invention dynamically adjusts the current to keep the LED brightness always close to the target value. It prevents the LED chip from being damaged due to excessive current and delays the light decay. It adapts to different input voltages, avoids invalid power consumption, and improves the overall energy efficiency. This formula plays the role of an "intelligent regulator" in the entire driving method and lays the foundation for subsequent strategies such as hybrid dimming and temperature compensation.

[0036] Step 202: Dynamically switch between the constant current dimming strategy and the linear dimming strategy according to the dimming threshold frequency of the light source.

[0037] In some embodiments, step 202 may include: Obtain a feedback resistor for stabilizing the gain and response of the circuit; Obtain a feedback capacitor for smoothing high-frequency noise and introducing phase compensation in the feedback loop; Determine the dimming threshold frequency according to the feedback resistor and the feedback capacitor; When the actual frequency of the light source is lower than the dimming threshold frequency, switch to the linear dimming strategy; when the actual frequency of the light source is higher than or equal to the dimming threshold frequency, switch to the constant current dimming strategy.

[0038] In some embodiments, the dimming threshold frequency is expressed as: ; Wherein, is the dimming threshold frequency, is the feedback resistor, is the feedback capacitor.

[0039] In specific implementation, is the final LED driving voltage (unit: volt, V), is the forward conduction voltage of the LED (unit: volt, V), which determines the minimum voltage required for the LED to start emitting light. is the drive current after temperature compensation (unit: ampere, A), is the parasitic resistance of the circuit (unit: ohm, Ω), including non-ideal factors such as PCB traces and inductor internal resistance, is the dynamic current change gain coefficient, used to amplify or suppress the impact of current transients on voltage (unit: ohm·second), is the instantaneous change rate of the compensation current (unit: ampere / second, A / s).

[0040] This formula is a dynamic adjustment model for the drive voltage, which combines the basic characteristics of the LED, parasitic losses, and transient response. It ensures that the LED can work quickly and stably under conditions such as brightness adjustment and temperature fluctuations.

[0041] Provides the minimum voltage required for the LED to emit light normally. Steady-state voltage compensation Compensates for the voltage drop across the parasitic resistance to avoid insufficient brightness caused by current loss. Dynamic response adjustment When the current changes rapidly, provides a transient voltage gain to prevent brightness jitter or current oscillation.

[0042] > 0, the current increases rapidly. To avoid an instantaneous jump in brightness caused by a sudden increase in current, the dynamic gain term provides an additional voltage to make the current rise gradually and smoothly. < 0, the current decreases rapidly. To prevent the brightness from suddenly dimming, the dynamic gain term reduces the voltage to make the brightness decay smoothly. ≈ 0, the dynamic gain term disappears, and the drive voltage depends only on the forward voltage of the LED and the voltage drop across the parasitic resistance.

[0043] Assume: = 3.2V (typical forward voltage of a single LED); = 500mA (compensated current); = 0.1Ω (trace and device parasitic resistance); = 0.05Ω⋅s; = 100mA / s (current change rate); Substitute into the formula: = 3.2+(0.5×0.1)+(0.05×0.1)= 3.255V; In the case of a slow increase in current, the drive voltage will stabilize at 3.255V.

[0044] If the current mutation accelerates, for example = 1000 mA / s, = 3.2 + 0.05+(0.05×1)=3.3 V.

[0045] The driving voltage will increase dynamically to prevent brightness jitter caused by rapid current mutation.

[0046] The present invention can ensure that the LED always operates in the optimal current range, avoiding brightness instability caused by overvoltage or undervoltage. The dynamic gain term absorbs the voltage fluctuations brought about by current mutation, eliminating brightness flicker. It avoids the redundant energy consumption caused by circuit parasitic losses, improving the overall driving efficiency.

[0047] The present invention uses an MCU to monitor the current change speed in real time, dynamically adjust the gain coefficient γ, and balance the response speed and stability. In the case of multiple LEDs connected in series, the parasitic resistance is split into tiny equivalent resistances for each LED, improving the compensation accuracy.

[0048] In summary, the present invention enables the LED driving circuit to not only have the steady-state operating ability but also quickly respond to current changes and suppress mutation interference. It is the voltage control core of the entire dimming strategy, ensuring stable light source output under various complex working conditions.

[0049] In some embodiments, the present invention further includes determining the final driving current of the light source in the linear dimming strategy, specifically as follows: Obtain the duty cycle representing the time ratio of the light source being turned on per unit time; Obtain the time decay coefficient used to describe the current decay characteristic of the light source over time; Obtain the current time during the dimming process; Determine the final driving current of the light source according to the duty cycle, the time decay coefficient, and the current time.

[0050] In some embodiments, the final driving current can be expressed as: ; where, is the final driving current, D is the duty cycle, is the time decay coefficient, and t is the time.

[0051] In specific implementation, the formula is used to describe the dynamic change process of the final driving current of the LED. This formula combines the duty cycle D and the time decay characteristic to achieve smooth brightness adjustment and dimming control.

[0052] This formula is mainly used in the linear dimming strategy, especially to avoid the stroboscopic problem caused by PWM dimming during low-frequency dimming. By introducing the time decay factor , it can achieve a smooth transition of the current, making the change in LED brightness more natural and reducing the visual flickering sensation.

[0053] is the final drive current, which is the LED drive current adjusted by the dimming strategy and directly determines the actual brightness of the LED.

[0054] is the initial set current (the adjusted initial current), which is the initial current value calculated before the dimming strategy and is usually calculated based on the input voltage and the target brightness in step 1. is an adjusted value. It provides a reference current for the dimming process.

[0055] D is the duty cycle. The duty cycle is an important parameter in dimming control and represents the proportion of the time that the LED is on within a unit time. The value range of the duty cycle is usually between 0 and 1 (or 0% to 100%). The higher the duty cycle, the higher the brightness of the LED; the lower the duty cycle, the lower the brightness.

[0056] is the time decay coefficient, which is a time-related decay coefficient used to describe the decay characteristic of the current over time. Its value determines the speed of the current transition. A larger value will make the current transition more rapid, while a smaller value will make the transition slower.

[0057] The time t represents the current time during the dimming process. It is used to calculate the dynamic change of the current over time to ensure the smoothness of the dimming process.

[0058] The D in the numerator represents the direct influence of the duty cycle on the current. The in the denominator is a dynamic adjustment term used to introduce the time decay characteristic.

[0059] The time decay term is an exponential decay function. As the time t increases, its value gradually decreases. When t = 0, = 1, and at this time the current is mainly determined by the initial current . As the time t increases, approaches 0, and the current gradually approaches × D.

[0060] At the beginning of dimming when t = 0, the current is: ; At this time, the current is affected by both the initial current and the duty cycle but has not reached the final value.

[0061] As time goes by, approaches 0, and the current gradually approaches: ; This is the final steady-state current of the dimming process, which is completely determined by the initial current and the duty cycle.

[0062] By introducing a time decay term , the formula can achieve a smooth transition of the current, avoiding the stroboscopic problem caused by sudden changes in the duty cycle in traditional PWM dimming. This smooth dimming is especially suitable for low-frequency dimming scenarios (such as below 100 Hz), which can significantly improve visual comfort.

[0063] The time decay coefficient can be selected to adjust the dynamic characteristics of dimming according to actual needs: a larger value makes the dimming process faster, suitable for scenarios that require a quick response. A smaller value makes the dimming process slower, suitable for scenarios that require a smooth transition.

[0064] The duty cycle D plays a key role in the formula, which directly determines the magnitude of the final steady-state current. By adjusting the duty cycle, dynamic adjustment from low brightness to high brightness can be achieved.

[0065] The value of needs to be optimized according to the actual application scenario. If is too large, the dimming process may be too fast, resulting in visual flicker; if is too small, the dimming process may be too slow, affecting the user experience. Usually, a suitable

[0066] value can be determined through experiments, making the dimming process both smooth and responsive.

[0067] The initial current is the basis of the dimming process, and its value needs to be accurately calculated according to the target brightness and input voltage. If the initial current is set improperly, it may cause brightness deviation during the dimming process.

[0068] The present invention realizes a smooth transition of the LED drive current by introducing a time decay characteristic, effectively solving the stroboscopic problem in low-frequency dimming. It combines the duty cycle and the time decay coefficient, and can dynamically adjust the dimming process according to actual needs. By reasonably selecting parameters, the performance of the dimming system can be optimized, improving visual comfort and user experience.

[0069] Step 203: Feed back the real-time temperature of the light source through a temperature sensor, and perform temperature compensation on the drive current of the light source to obtain a compensated current.

[0070] In some embodiments, step 203 may include: Obtain the real-time temperature of the light source; Obtain the reference temperature of the light source under standard working conditions; Obtain a temperature compensation coefficient for quantifying the influence degree of temperature change on the brightness of the light source; Determine the compensation current according to the final drive current, real-time temperature, reference temperature and temperature compensation coefficient of the light source.

[0071] In some embodiments, the compensation current may be expressed as: ; where is the compensation current, T is the real-time temperature, is the reference temperature, is the temperature compensation coefficient.

[0072] In specific implementation, the luminous efficiency of the LED will decrease as the temperature increases. This is because the increase in temperature will cause the carrier recombination efficiency inside the LED chip to decrease, resulting in a reduction in the light output under the same current. To compensate for the influence of this temperature change on the brightness, it is necessary to dynamically adjust the drive current of the LED according to the real-time temperature.

[0073] is the compensation current, is the current finally used to drive the LED. After temperature compensation, it can ensure that the LED maintains a relatively stable brightness at different temperatures.

[0074] is the final drive current, which is the LED drive current calculated according to the target brightness without considering temperature compensation. It is the basic input value of the temperature compensation formula.

[0075] T is the real-time temperature, which is the current temperature of the LED chip measured by a temperature sensor. The temperature sensor is usually placed close to the LED to monitor the temperature change in real time.

[0076] is the reference temperature, which is a preset reference temperature, usually determined during the LED design or test phase. At the reference temperature, the luminous efficiency of the LED is considered to be standard. For example, the reference temperature can be room temperature (25°C).

[0077] is the temperature compensation coefficient. This is a key parameter for quantifying the influence degree of temperature change on the brightness of the LED. It is a proportionality coefficient, usually determined through experiments. For example, if the brightness of the LED decreases by 1% when the temperature increases by 1°C, then The value of may be close to 0.01 (1%).

[0078] The core of the formula is to adjust the current through the temperature difference to compensate for the impact of temperature changes on brightness. The specific steps are as follows: Calculate the temperature difference , which calculates the difference between the current temperature and the reference temperature. The positive or negative value of the temperature difference indicates whether the current temperature is higher or lower than the reference temperature.

[0079] Calculate the temperature compensation factor , which multiplies the temperature difference by the temperature compensation coefficient to obtain a proportionality factor. This factor represents the relative impact of temperature changes on current adjustment.

[0080] Calculate the compensated current . Finally, subtract the temperature compensation factor from 1 and then multiply by the uncompensated current . The purpose of this step is to adjust the current according to temperature changes to maintain the stability of the LED's brightness.

[0081] The temperature compensation factor is a proportional value used to adjust the current. When the temperature rises, > 0, the compensation factor is positive and the current will decrease; when the temperature drops, < 0, the compensation factor is negative and the current will increase. This adjustment method ensures that the LED can maintain a relatively stable brightness at different temperatures.

[0082] is a key parameter that determines the sensitivity of current adjustment to temperature changes. If is too large, the current adjustment may be too drastic; if is too small, the current adjustment may not be sufficient to compensate for the brightness change. Usually, it is necessary to determine the appropriate value through experiments.

[0083] In practical applications, the temperature compensation formula assumes that the temperature change is linear within a certain range. However, if the temperature change is too large, this linear assumption may no longer hold. Therefore, the formula is applicable to scenarios with relatively small temperature changes (for example, within the range of ±20°C). If the temperature change exceeds this range, a more complex compensation model may be required.

[0084] The effect of temperature compensation depends on the accuracy of the temperature sensor. If the error of the temperature sensor is large, it may lead to inaccurate current adjustment. Therefore, it is very important to select a high-precision temperature sensor. Since temperature changes are dynamic, it is necessary to monitor the temperature in real time and adjust the current dynamically. This requires the system to have a fast response ability to ensure the stability of brightness. In practical applications, it is necessary to verify the temperature compensation coefficient through experiments Rationality. By measuring the brightness and current of the LED at different temperatures, the value can be adjusted until the best compensation effect is found.

[0085] When , at the reference temperature, the temperature compensation factor is zero, and the compensated current is equal to the uncompensated current, indicating that the current does not need to be adjusted at the reference temperature.

[0086] When T is much higher than if the temperature is much higher than the reference temperature is positive and large, the compensation factor is close to 1, which may cause to approach zero. In this case, the maximum value of the compensation factor needs to be limited to avoid the LED from turning off due to too low current.

[0087] When T is much lower than if the temperature is much lower than the reference temperature, is negative and large, the compensation factor is negative, which may cause to exceed . In this case, the minimum value of the compensation factor needs to be limited to avoid damaging the LED due to too high current.

[0088] The present invention realizes the dynamic adjustment of the LED current through a simple linear relationship to compensate for the influence of temperature change on brightness. It is an effective solution applicable to most scenarios with relatively small temperature changes. However, in practical applications, attention needs to be paid to the accuracy of the temperature sensor, the real-time performance of dynamic adjustment, and the reasonable selection of the temperature compensation coefficient. Through experimental verification and optimization, it can be ensured that the LED can maintain stable brightness and a long service life at different temperatures.

[0089] Step 204: Determine the driving voltage of the light source by combining the forward voltage of the light source and the compensation current.

[0090] In some embodiments, step 204 may include: Obtain the minimum forward voltage required to provide normal light emission of the light source; Obtain the circuit parasitic resistance of the light source; Obtain the dynamic current change gain for amplifying or suppressing the influence of current transients on voltage; Determine the driving voltage of the light source according to the compensation current, the circuit parasitic resistance, and the dynamic current change gain.

[0091] In some embodiments, the driving voltage can be expressed as: ; where is the driving voltage, is the forward voltage, is the circuit parasitic resistance, is the dynamic current change gain.

[0092] In a specific implementation, is the final LED drive voltage (unit: volt, V), is the forward conduction voltage of the LED (unit: volt, V), which determines the minimum voltage required for the LED to start emitting light, is the drive current after temperature compensation (unit: ampere, A), is the parasitic resistance of the circuit (unit: ohm, Ω), including non-ideal factors such as PCB traces and inductor internal resistance, is the dynamic current change gain coefficient, which is used to amplify or suppress the impact of current transients on voltage (unit: ohm·second), is the instantaneous change rate of the compensation current (unit: ampere / second, A / s).

[0093] This formula is a dynamic adjustment model for the drive voltage, which combines the basic characteristics of the LED, parasitic losses, and transient response. It ensures that the LED can work quickly and stably under conditions such as brightness adjustment and temperature fluctuations.

[0094] Provides the minimum voltage required for the LED to emit light normally. Steady-state voltage compensation Compensates for the voltage drop across the parasitic resistance to avoid insufficient brightness caused by current loss. Dynamic response adjustment When the current changes rapidly, provides a transient voltage gain to prevent brightness jitter or current oscillation.

[0095] > 0, the current increases rapidly. To avoid an instantaneous jump in brightness caused by a sudden increase in current, the dynamic gain term provides an additional voltage to make the current rise gradually and smoothly. < 0, the current decreases rapidly. To prevent the brightness from suddenly dimming, the dynamic gain term reduces the voltage to make the brightness decay smoothly. ≈ 0, the dynamic gain term disappears, and the drive voltage depends only on the LED forward voltage and the parasitic resistance voltage drop.

[0096] Assume: = 3.2V (typical forward voltage of a single LED); = 500mA (compensated current); = 0.1Ω (trace and device parasitic resistance); = 0.05Ω⋅s; = 100 mA / s (rate of change of current); Substitute into the formula: = 3.2 + (0.5 × 0.1) + (0.05 × 0.1) = 3.255 V; When the current rises slowly, the driving voltage will stabilize at 3.255 V.

[0097] If the current mutation accelerates, for example = 1000 mA / s, = 3.2 + 0.05 + (0.05 × 1) = 3.3 V.

[0098] The driving voltage will rise dynamically to prevent brightness jitter caused by rapid current mutation.

[0099] The present invention can ensure that the LED always operates in the optimal current range, avoiding brightness instability caused by overvoltage or undervoltage. The dynamic gain term absorbs the voltage fluctuations brought by current mutation and eliminates brightness flicker. It avoids the extra energy consumption caused by circuit parasitic losses and improves the overall driving efficiency.

[0100] The present invention uses an MCU to monitor the current change speed in real time, dynamically adjusts the gain coefficient γ, and balances the response speed and stability. In the case of multiple LEDs in series, the parasitic resistance is split into tiny equivalent resistances for each LED to improve the compensation accuracy.

[0101] In summary, the present invention enables the LED driving circuit to not only have the steady-state working ability but also quickly respond to current changes and suppress mutation interference. It is the voltage control core of the entire dimming strategy, ensuring stable light source output under various complex working conditions.

[0102] Step 205, based on PID closed-loop control, adjust the duty cycle in real time to obtain the real-time duty cycle, and adjust the light source to match the target brightness based on the real-time duty cycle and the driving voltage.

[0103] In some embodiments, step 205 may include: Obtain the brightness error of the difference between the target brightness and the actual brightness of the light source; Obtain the PID control parameters for calculating the real-time duty cycle; Determine the real-time duty cycle according to the duty cycle of the light source at the previous time point, the PID control parameters, and the brightness error.

[0104] In some embodiments, the real-time duty cycle can be expressed as: ; Wherein, is the real-time duty cycle at the current time, is the brightness error, are PID control parameters.

[0105] In specific implementation, is the real-time duty cycle D(t−1) of the current time: the duty cycle of the previous time point. is the brightness error, that is, the difference between the target brightness and the actual brightness. is the proportional gain coefficient, which determines the direct influence degree of the error on the duty cycle adjustment. is the integral gain coefficient, which determines the long-term influence of the cumulative error on the duty cycle. is the differential gain coefficient, which determines the transient correction intensity of the error change speed on the duty cycle.

[0106] This formula is a PID controller (Proportional-Integral-Derivative controller), which is widely used in the field of automatic control. It dynamically adjusts the PWM duty cycle of the LED according to the real-time brightness error, so as to accurately control the brightness.

[0107] Proportional term Immediate response: The larger the brightness error, the greater the adjustment amplitude of the duty cycle. If the brightness is insufficient, increase the duty cycle; if the brightness is too high, decrease the duty cycle.

[0108] Integral term , cumulative error correction: Small errors that exist for a long time gradually accumulate, driving the duty cycle to be slowly adjusted to the accurate value. For example: If the LED brightness is low for a long time, the integral term will gradually increase the duty cycle to eliminate the steady-state error.

[0109] Differential term , suppressing mutations: If the brightness error changes rapidly (such as input voltage fluctuations), the differential term will react immediately and quickly adjust the duty cycle to prevent the brightness from jittering instantaneously.

[0110] When the brightness is insufficient (e(t) > 0): Increase the duty cycle, increase the LED current, and increase the brightness. When the brightness is too high (e(t) < 0): Decrease the duty cycle, decrease the LED current, and decrease the brightness.

[0111] When the error increases rapidly ( > 0): The brightness suddenly drops, and the differential term immediately increases the duty cycle to quickly restore the brightness.

[0112] When the error accumulates slowly: If the brightness error exists for a long time, the integral term gradually adjusts, and the duty cycle slowly approaches the perfect value.

[0113] Example calculation, assuming: Target brightness: 1000 lumens; Actual brightness: 900 lumens; Initial duty cycle: D(t−1) = 0.6; PID parameters: = 0.05, = 0.01, = 0.02; Current error: e(t) = 1000 - 900 = 100; Rate of change of error: de(t) / dt = 10 lm / s; Integral value of error: ∫e(t) dt = 500; Substitute into the formula: D(t) = 0.6 + 10.2 = 0.702.

[0114] The duty cycle increases, the LED current increases, and the brightness gradually approaches the target value, and the final error gradually converges.

[0115] The LED brightness always stably tracks the target value with extremely small error. The PID controller can quickly respond to external interferences such as input voltage fluctuations and temperature changes. The integral term corrects the cumulative error to ensure that the brightness will not gradually deviate from the target during long-term operation.

[0116] The present invention can dynamically adjust the PID parameters according to the ambient light and the degree of LED aging. An overly large integral term may cause the system to get out of control, and an integral limit can be added to prevent the duty cycle from exceeding the range. A filter is added to the differential channel to suppress the interference of high-frequency noise on the brightness adjustment.

[0117] The PID controller of the present invention is the core control module of the entire driving scheme, making the LED dimming process intelligent, smooth and jitter-free, and perfectly adapting to complex working conditions. Whether it is slow brightness adjustment or transient mutation, the system can quickly return to the ideal state.

[0118] Please refer to Figure 2 , Figure 2 , which is a schematic structural diagram of a driving system for an adjustable light source LED provided by the present invention.

[0119] As Figure 2 shown, a driving system for an adjustable light source LED proposed in an embodiment of the present invention includes: A current calculation module 301 for real-time collecting the input voltage and the target brightness of the light source and calculating the initial current setting value of the light source; A strategy switching module 302 for dynamically switching between a constant current dimming strategy and a linear dimming strategy according to the dimming threshold frequency of the light source; A current compensation module 303 for feeding back the real-time temperature of the light source through a temperature sensor and performing temperature compensation on the driving current of the light source to obtain a compensated current; A driving voltage module 304 for determining the driving voltage of the light source by combining the forward voltage of the light source and the compensated current; The light source adjustment module 305 is used to adjust the duty cycle in real time based on PID closed-loop control to obtain a real-time duty cycle, and adjust the light source to match the target brightness based on the real-time duty cycle and the driving voltage.

[0120] Please refer to Figure 3 , Figure 3 which is a schematic diagram of an embodiment of an electronic device provided by an embodiment of the present invention. As Figure 3 shown, an embodiment of the present invention provides an electronic device 400, including a memory 410, a processor 420, and a computer program 411 stored on the memory 410 and executable on the processor 420. When the processor 420 executes the computer program 411, the following steps are implemented: Collect the input voltage and target brightness of the light source in real time, and calculate the initial current setting value of the light source; Dynamically switch the constant current dimming strategy and the linear dimming strategy according to the dimming threshold frequency of the light source; Feed back the real-time temperature of the light source through a temperature sensor, and perform temperature compensation on the driving current of the light source to obtain a compensated current; Combine the forward voltage of the light source and the compensated current to determine the driving voltage of the light source; Adjust the duty cycle in real time based on PID closed-loop control to obtain a real-time duty cycle, and adjust the light source to match the target brightness based on the real-time duty cycle and the driving voltage.

[0121] Please refer to Figure 4 , Figure 4 which is a schematic diagram of an embodiment of a computer-readable storage medium provided by an embodiment of the present invention. As Figure 4 shown, this embodiment provides a computer-readable storage medium 500, on which a computer program 411 is stored. When the computer program 411 is executed by a processor, the following steps are implemented: Collect the input voltage and target brightness of the light source in real time, and calculate the initial current setting value of the light source; Dynamically switch the constant current dimming strategy and the linear dimming strategy according to the dimming threshold frequency of the light source; Feed back the real-time temperature of the light source through a temperature sensor, and perform temperature compensation on the driving current of the light source to obtain a compensated current; Combine the forward voltage of the light source and the compensated current to determine the driving voltage of the light source; Adjust the duty cycle in real time based on PID closed-loop control to obtain a real-time duty cycle, and adjust the light source to match the target brightness based on the real-time duty cycle and the driving voltage.

[0122] It should be noted that in the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0123] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0124] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram can be realized by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a system for realizing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0125] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction system, and the instruction system realizes the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0126] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for realizing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0127] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0128] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A driving method for an adjustable light source LED, characterized in that: The method comprises: Collecting the input voltage and target brightness of the light source in real time, and calculating the initial current setting value of the light source; Dynamically switching between a constant current dimming strategy and a linear dimming strategy according to a dimming threshold frequency of the light source; Feedback the real-time temperature of the light source through a temperature sensor, perform temperature compensation on the driving current of the light source, and obtain a compensation current; Determine the driving voltage of the light source by combining the forward voltage of the light source and the compensation current; The duty cycle is adjusted in real time based on the PID closed-loop control to obtain a real-time duty cycle, and the light source is adjusted to match the target brightness based on the real-time duty cycle and the driving voltage.

2. The driving method for an adjustable light source LED according to claim 1, characterized in that: The real-time acquisition of the input voltage and target brightness of the light source and calculation of the initial current setting value of the light source include: Obtaining a default initial current value of the light source; Acquire a brightness correction coefficient for matching the nonlinear relationship between the target brightness and the current; Acquiring a sampling resistance value for real-time detection of the current of the light source; According to the input voltage of the light source, the target brightness, the sampling resistance value and the brightness correction coefficient, the initial current default value of the light source is processed to calculate the initial current setting value of the light source.

3. The driving method for an adjustable light source LED according to claim 2, characterized in that: The initial current setting value is expressed as: ; in, is the initial current setting value, is the target brightness, is the input voltage, is the sampling resistor value, is the initial current default value, is the brightness correction factor.

4. The driving method for an adjustable light source LED according to claim 3, characterized in that: The method of dynamically switching between the constant current dimming strategy and the linear dimming strategy according to the dimming threshold frequency of the light source includes: Obtaining feedback resistors to stabilize the gain and response of the circuit Get the feedback capacitor used to smooth high frequency noise and introduce phase compensation in the feedback loop; Determining a dimming threshold frequency according to the feedback resistor and the feedback capacitor; When the actual frequency of the light source is lower than the dimming threshold frequency, the linear dimming strategy is switched to; when the actual frequency of the light source is higher than or equal to the dimming threshold frequency, the constant current dimming strategy is switched to.

5. The driving method for an adjustable light source LED according to claim 4, characterized in that: The dimming threshold frequency is expressed as: ; in, is the dimming threshold frequency, is the feedback resistor, is the feedback capacitor.

6. The driving method for an adjustable light source LED according to claim 5, characterized in that: The method further includes determining a final driving current of the light source in the linear dimming strategy; the final driving current is determined by the following steps: Obtaining a duty cycle representing the proportion of time the light source is turned on per unit time; Obtaining a time decay coefficient for describing the time decay characteristics of the current of the light source; Get the current time during the dimming process; A final driving current of the light source is determined according to the duty cycle, the time decay coefficient and the current time.

7. The driving method for an adjustable light source LED according to claim 6, characterized in that: The method of feeding back the real-time temperature of the light source through a temperature sensor and performing temperature compensation on the driving current of the light source to obtain the compensation current comprises: Obtaining the real-time temperature of the light source; Obtaining a reference temperature of the light source under standard working conditions; Obtaining a temperature compensation coefficient for quantifying the degree of influence of temperature change on the brightness of the light source; The compensation current is determined according to the final driving current of the light source, the real-time temperature, the reference temperature and the temperature compensation coefficient.

8. The driving method for an adjustable light source LED according to claim 7, characterized in that: The step of combining the forward voltage of the light source with the compensation current to determine the driving voltage of the light source includes: Obtaining a minimum forward voltage required for providing the light source with normal light emission; Obtaining a circuit parasitic resistance of the light source; Obtaining a dynamic current change gain for amplifying or suppressing the effect of current transients on voltage; The driving voltage of the light source is determined according to the compensation current, the circuit parasitic resistance and the dynamic current change gain.

9. The driving method for an adjustable light source LED according to claim 8, characterized in that: The real-time adjustment of the duty cycle based on the PID closed-loop control to obtain the real-time duty cycle includes: Obtaining a brightness error between the target brightness and the actual brightness of the light source; Obtaining PID control parameters for calculating the real-time duty cycle; The real-time duty cycle is determined according to the duty cycle of the light source at a previous time point, the PID control parameter and the brightness error.

10. A driving system for an adjustable light source LED, characterized in that: The system comprises: A current calculation module, used to collect the input voltage and target brightness of the light source in real time and calculate the initial current setting value of the light source; A strategy switching module, used to dynamically switch between a constant current dimming strategy and a linear dimming strategy according to a dimming threshold frequency of the light source; A current compensation module, used to feed back the real-time temperature of the light source through a temperature sensor, perform temperature compensation on the driving current of the light source, and obtain a compensation current; A driving voltage module, used to determine the driving voltage of the light source by combining the forward voltage of the light source and the compensation current; The light source adjustment module is used to adjust the duty cycle in real time based on the PID closed-loop control to obtain a real-time duty cycle, and adjust the light source to match the target brightness based on the real-time duty cycle and the driving voltage.

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